CVE-2006-6500:Heap-based buffer overflow in Mozilla Firefox 2.x before 2.0.0.1, Firefox 1.5.x before 1.5.0.9, Thunderbird before 1.5.0.9, and SeaMonkey before 1.0.7, which allows remote attackers to crash the application and possibly execute arbitrary code by setting the CSS cursor to certain images that trigger an incorrect size calculation when converting to a Windows bitmap.

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This vulnerability is a heap-based buffer overflow in multiple Mozilla-based applications (Firefox 2.x up to 2.0.0.1, Firefox 1.5.x up to 1.5.0.9, Thunderbird up to 1.5.0.9, and SeaMonkey up to 1.0.7). An attacker can remotely exploit the flaw by providing a specially crafted image used as a CSS cursor, causing an incorrect size calculation during conversion to a Windows bitmap. Successful exploitation can lead to a denial of service (crash) and potentially arbitrary code execution on the affected system.

Overview

The CVE describes a remote vulnerability in widely used Mozilla-derived browsers and mail clients where a crafted CSS cursor image triggers a heap-based overflow during Windows bitmap conversion. This can crash the application and may allow arbitrary code execution, depending on the context and ASLR/DEP mitigations in place. Affected products include Firefox 2.x (pre-2.0.0.1) and 1.5.x (pre-1.5.0.9), Thunderbird (pre-1.5.0.9), and SeaMonkey (pre-1.0.7). Public disclosure dates and a breadth of vendor advisories followed, with patches issued in subsequent security updates.

Remediation

  1. Inventory: Identify all instances of Firefox (2.x and 1.5.x), Thunderbird, and SeaMonkey in use within the environment and note their versions.
  2. Upgrade to patched versions:
    • Firefox: upgrade to 2.0.0.1 or newer
    • Firefox (1.5.x line): upgrade to 1.5.0.9 or newer
    • Thunderbird: upgrade to 1.5.0.9 or newer
    • SeaMonkey: upgrade to 1.0.7 or newer
  3. Apply official advisories and patches: Ensure all relevant vendor/security advisories are applied and that automatic updates are enabled where feasible.
  4. Verification: After patching, verify that the patched versions are running and conduct basic sanity checks to ensure browser functionality. If feasible, validate that the vulnerability cannot be triggered in the patched versions (e.g., by applying a controlled test image in a safe environment).
  5. Mitigation and defense-in-depth: If immediate upgrades are not possible, implement compensating controls such as restricting or blocking remote content that could supply crafted cursor images, and enforce broader browser security hardening and network segmentation until patches can be applied.
  6. Monitoring: Stay current with security advisories (vendor, CERT, Secunia, etc.) for any related follow-ups and ensure timely patching for affected systems.

References

Industry ExposureMost to least
This section illustrates the prevalence of a specific Common Vulnerabilities and Exposures (CVE) across various industries based on customer reports. The ranking displays industries from the most to least affected by this particular vulnerability, offering valuable insight into where this CVE has been most frequently observed. This information can help organizations within these sectors prioritize their security efforts, understand their relative risk exposure compared to their peers, and focus remediation strategies where they are most needed. By understanding the industry-specific impact, organizations can make more informed decisions regarding patching, resource allocation, and overall risk management related to this CVE.

  1. Manufacturing: Low
    Manufacturing
  2. Construction: Low
    Construction
  3. Wholesale Trade: Low
    Wholesale Trade
  4. Accommodation & Food Services: Low
    Accommodation & Food Services
  5. Administrative, Support, Waste Management & Remediation Services: Low
    Administrative, Support, Waste Management & Remediation Services
  6. Agriculture, Forestry Fishing & Hunting: Low
    Agriculture, Forestry Fishing & Hunting
  7. Arts, Entertainment & Recreation: Low
    Arts, Entertainment & Recreation
  8. Educational Services: Low
    Educational Services
  9. Finance and Insurance: Low
    Finance and Insurance
  10. Health Care & Social Assistance: Low
    Health Care & Social Assistance
  11. Information: Low
    Information
  12. Management of Companies & Enterprises: Low
    Management of Companies & Enterprises
  13. Mining: Low
    Mining
  14. Other Services (except Public Administration): Low
    Other Services (except Public Administration)
  15. Professional, Scientific, & Technical Services: Low
    Professional, Scientific, & Technical Services
  16. Public Administration: Low
    Public Administration
  17. Real Estate Rental & Leasing: Low
    Real Estate Rental & Leasing
  18. Retail Trade: Low
    Retail Trade
  19. Transportation & Warehousing: Low
    Transportation & Warehousing
  20. Utilities: Low
    Utilities

Focus on What Matters

  1. See Everything.
  2. Identify True Risk.
  3. Proactively Mitigate Threats.

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